A synthetic cannabinoid known as PTC, which stands for "pète ton crâne" (French for "pop your skull"), has raised concerns among health officials due to its severe effects on adolescents. This substance contains compounds like 5F-AKB4, which are up to 100 times more potent than the main component of marijuana, tetrahydrocannabinol (THC). Unlike traditional cannabis, PTC is not detectable by standard urine tests, making it harder to identify in drug screenings. It is often found in e-liquids used in vaping devices and was classified as a narcotic in France in 2017. Despite this classification, its use has grown among young people, especially through vaping. The effects of PTC can be unpredictable and dangerous, ranging from vomiting and convulsions to strokes, coma, or even death. It can also cause severe headaches, sudden anxiety, sleep disturbances, or an increased heart rate known as tachycardia. A study published in January 2026 in the Journal of School Health found that adolescents who use these synthetic cannabinoids are at a higher risk of experiencing cranial trauma—damage to the head or brain—possibly due to the intense physical reactions caused by the drug. In 2024, multiple cases of PTC poisoning led to the hospitalization of 15-year-olds, sometimes as part of peer challenges where individuals compete to take increasingly dangerous substances. The French National Agency for Safety in Health (ANSM) has issued warnings about the dangers of mixing synthetic cannabinoids with other drugs, which can lead to overdoses and serious health complications. These interactions can amplify the effects of the substances, increasing the risk of severe illness or death. Some symptoms that require immediate medical attention include violent and unusual headaches, sudden anxiety or paranoia, changes in sleep or behavior, and a rapid heartbeat or feelings of discomfort after use. Because standard urine tests do not detect PTC, some young people may believe they are not at risk of being caught if they use it. Experts emphasize that open communication and non-judgmental support from adults are essential in identifying early signs of PTC use. As the school year begins, many are calling for honest and direct conversations between adults and young people to address this growing public health issue.